1. Field of Invention
The present invention relates to a mobile phone; and, more particularly, to a mobile phone having a camera and a signal processor for sending and receiving camera signals to/from the internet.
Future mobile terminals will need to be capable of sending multimedia messages from phone to phone and phone to internet and vice versa. An integrated or an accessory digital camera is, therefore, a useful additional function in a mobile phone.
2. Description of Related Art
FIG. 1 shows a known digital camera generally indicated as 10 using complimentary metal oxide semiconductor (CMOS) sensor technologies and a digital signal processor (DSP) for camera control and format conversions, e.g., color filter array interpolation and red/green/blue (RGB) to digital component video conversion. Color filter arrays are known in the art, and a Bayer color filter array is one example of the same which is described in U.S. Pat. No. 4,605,956 (issued to Eastman Kodak). U.S. Pat. No. 4,605,956 discloses a single-chip electronic color camera with color-dependent birefringent optical spatial frequency filter and red and blue signal interpolating circuits, which provides a way for generating interpolated RGB from a single sensor.
The digital camera 10 includes a camera module 11 having a lens/filter combination 12, a timing generator 14 for performing timing functions and a CMOS image sensor 16 using a common intermediate format (CIF) or a video graphics array (VGA) for performing image sensing functions. In operation, frame size in video capture and still picture capture are different so that a conversion from a video graphics array (VGA) sensor data to common interface format (CIF) or other video frame size is carried out in the data format conversion function 34 as a DSP 30 software algorithm.
The camera module 11 also has an automatic exposure control 18 for performing automatic time control functions, an interface 20 having a correlated double sampling (CDS) circuit 22 for performing correlated double sampling functions, an automatic gain control (AGC) circuit 24 for performing automatic gain control functions, an analog-to-digital conversion circuit 26 (ADC) for performing analog-to-digital conversion functions, an automatic white balance circuit (AWB) 28 for performing automatic white balance functions, a digital signal processor 30 with a frame memory 34 for performing digital signal processing functions, a data format conversion module 34 for performing data format conversion functions, and a digital control interface module 36 for performing digital control interface functions.
Mobile phones are built using customized integrated circuits to gain small size. These circuits are using the latest low power processing technology and it is, therefore, desirous to integrate as much processing into this circuitry as possible. It is desirous to remove as much functionalities from the camera module 11 as possible in order to make it possible to build a single chip camera module.